[jimduchek]

Intriguing. Yeah, I think if the ESS had failed in such a way it was shorting the 5V supply to ground, it might cause the PCM not to boot. That's not a typical failure case for a solid-state part like that, but I guess nothing's impossible. Would suggest checking the pins at the ESS connector for continuity to chassis ground first (The ESS harness has a couple places it might rub, especially if a PO or mechanic did not route it properly), but seems like replacing the ESS is the way to go.

 

[texasprd]

Do you have a clamp-style amp meter, or an inductive amp pickup you can connect to a regular multimeter? Here's an interesting article describing how to find s shorted sensor. Summary: test the power draw of multiple 5V reference signals - a shorted reference wire (and I should think an internally shorted sensor, too) will draw more current. Note that the amperages are very low, even for the shorted sensor.

The '96 FSM says the sensor troubleshooting procedure is in the powertrain diagnostic manual. JimDuchek posted about the manual here: 1997 Powertrain Diagnostics Manual -- Merry early Xmas

I didn't see the powertrain manual in the FSM stickies, but if it's there - even if for a different year - the ESS testing should be the same as far as resistance values

 

[[email protected]]

First thing first, have you checked for communications from the PCM? If none, there's your problem. You were probably driving in limp mode and didn't notice it.

 

[GAmes]

. You were probably driving in limp mode and didn't notice it.

Limp mode in a 2nd gen 12 valve? Really?

 

[jimduchek]

Limp mode in a 2nd gen 12 valve? Really?

A good 8 hour day on that suspension puts me into limp mode sometimes

 

[RollDUPwood]

That K4 sensor ground is spliced near the fuel filter in the harness and those splices branch out from there. I checked continuity from the engine harness connector where the ESS is located to the PCM and everything was good. Luckily Amazon has the generic ESS for 50$. Part# Standard PC756. I know it’s the cheapo but I figured I’d try it. And it works. Thank you all for your input. I noticed in the FSM in the wiring diagram chapter 8W-30 there is a ton of information at the beginning explaining how the system works and what controls what.

 

[RollDUPwood]

Limp mode in a 2nd gen 12 valve? Really?

Yes your probably right but I did the nv4500 swap 2 months ago and didn’t notice anything regarding the transmission because I don’t have the auto anymore.